“PNETs often appear as solid hypervascular neoplasms on arterial or occasionally portal venous phase imaging. Prior work suggests that approximately 22% of PNETs contain calcification, similar to our study. Although MPD dilation is more commonly seen secondary to pancreatic adenocarcinoma rather than PNETs, a minority of PNETs have been found to cause MPD dilation, which may be due to mass effect from the tumor itself or from fibrotic stricture formation secondary to serotonin or related metabolites released by the tumor. In our study, we found that up to one-quarter of PNETs had associated MPD dilation, whereas this finding was not present for any pancreatic RCC metastases.”Differentiation of pancreatic neuroendocrine tumors from pancreas renal cell carcinoma metastases on CT using qualitative and quantitative features van der Pol CB et al.Abdominal Radiology2019 (in press)

Our results suggest that imaging features at enhanced CT may accurately differentiate between pancreatic RCC metastases and PNET and could potentially obviate the need for his- tological confirmation, especially to confirm the presence of metastatic disease in patients with a history of RCC, although will require confirmation in larger sample sizes. Differentiation of pancreatic neuroendocrine tumors from pancreas renal cell carcinoma metastases on CT using qualitative and quantitative features van der Pol CB et al.Abdominal Radiology2019 (in press)

“Although the field of high-dimensional QCT TA is still under development, the literature suggests that QCT TA can be used for characterizing lesions or tumors, predicting staging, nuclear grading, assessing the response to treatment, and predicting survival.”Radiogenomics in Clear CellRenal Cell Carcinoma: Machine Learning–Based High-Dimensional Quantitative CT Texture Analysis in Predicting PBRM1 Mutation StatusKocak B et al.AJR 2019; 212:1–9

“Renal cell carcinoma (RCC) is a significant malignancy; 63 000 individuals in the United States were newly diagnosed with RCC in 2017. Approximately 90% of all renal tumors are RCCs, and 76% of RCCs are the clear cell subtype, 17% are papillary, and 6% are the chromophobe subtype. In the United States, the incidence of RCC continues to increase, in part because of high rates of obesity, hypertension, smoking, and exposure to other risk factors and also because of improved tumor detection due to increased use of imaging and advances in imaging technology. Collectively, these factors have led to a progressive decrease in the size of renal masses at initial detection such that localized kidney cancers now represent more than 60% of the detected cases of renal cancer. “2017 AUA Renal Mass and Localized Renal Cancer Guidelines: Imaging Implications Ward RD et al.RadioGraphics 2018 (in press)

The AUA guideline for performing RN stipulates that physicians should consider RN in cases in which tumor size, RMB results, and/or imaging characteristics suggest increased oncologic potential. In this setting, RN is preferred when all of the following criteria are met: (a) there is high tumor complexity and PN would be challenging, even in experienced hands; (b) there is no preexisting CKD or proteinuria; and (c) the contralateral kidney is normal and the new baseline estimated glomerular filtration rate will likely be greater than 45 mL/min/1.73 m2.2017 AUA Renal Mass and Localized Renal Cancer Guidelines: Imaging Implications Ward RD et al.RadioGraphics 2018 (in press)

The AUA guidelines for performing PN include the following: (a) PN should be a priority for management of cT1a renal masses when intervention is indicated. (b) Nephron-sparing approaches should be a priority for patients with an anatomic or functionally solitary kidney, bilateral tumors, known familial RCC, preexisting CKD, or proteinuria. (c) Nephron-sparing approaches should be considered for patients who are young, have multifocal masses, or have comorbidities that are likely to affect renal function in the future. 2017 AUA Renal Mass and Localized Renal Cancer Guidelines: Imaging Implications Ward RD et al.RadioGraphics 2018 (in press)

AUA guidelines for active surveillance include the following recommendations: (a) Active surveillance is an option for initial management in patients with renal masses suspicious for cancer, especially those smaller than 2 cm. (b) Active surveillance or expectant management should be a priority when the anticipated risk of intervention or competing risks of death outweigh the potential oncologic benefits of active treatment.2017 AUA Renal Mass and Localized Renal Cancer Guidelines: Imaging Implications Ward RD et al.RadioGraphics 2018 (in press)

“For preoperative evaluation, arterial phase CT scans obtained with a 30-second delay can help to detect renal arterial branches and their relationship to the tumor. In addition, excretory phase images can be used to identify the position of the collecting system in relation to the mass.” 2017 AUA Renal Mass and Localized Renal Cancer Guidelines: Imaging Implications Ward RD et al.RadioGraphics 2018 (in press)

The management of RCC is evolving and becoming less aggressive, in part because of the recognition that many renal tumors, especially small ones, are indolent. In light of these findings, the roles of RMB and management techniques such as thermal ablation and active surveillance are becoming increasingly important. Additional data suggest that postprocedural kidney function may be an important factor in long-term survival, shifting the preference from RN to nephron- sparing techniques such as PN and thermal ablation. The radiologist has an essential role in the evaluation, counseling, and selective treatment of patients with localized kidney cancer. 2017 AUA Renal Mass and Localized Renal Cancer Guidelines: Imaging Implications Ward RD et al.RadioGraphics 2018 (in press)

“Differentiation between benign and metastatic adrenal masses in patients with RCC can be achieved accurately by combining multiple imaging features on contrast-enhanced CT.”

“Adrenal metastasis is reported to occur in 1.2–10% of patients with renal cell carcinoma (RCC). On the other hand, adrenal incidentalomas, which are discovered at radiologic examinations conducted for indications other than adrenal disease, are relatively common, occurring in approximately 3–7% of the adult population, and most are benign. Given the frequency of adrenal metastasis in patients with RCC and the frequency of incidentaloma in the general population, it is expected that approximately half of adrenal masses in patients with RCC are metastases.”

“Choi et al. reported that adrenal metastases from hypervascular primary extraadrenal malignancies, such as RCC or hepatocellular carcinoma, showed a wash- out pattern similar to that of adrenal adenoma .”

“The size of the adrenal mass is an important variable in predicting malignancy .If an adrenal mass is larger than 4 cm, it is usually thought to be malignant. The adrenal masses larger than 4 cm in our population also had high predictive value for metastasis. On the contrary, smaller adrenal mass tended to be benign. However, there was substantial overlap between benign and metastatic adrenal masses with small size.”

“The CT attenuation values of metastatic adrenal masses were statistically significantly higher than those of benign masses in both the corticomedullary phase and nephrographic phase. According to Choi et al., the attenuation values of metastases from RCCs (n = 16) and hepatocellular carcinomas (n = 3) on 1-minute contrast-enhanced CT were significantly higher than those of adenomas. They also reported that attenuation values of greater than 140 HU included 37% (7/19) or 32% (6/19) of metastases, whereas no cases of adenomas were included. Our observation was similar to their result; attenuation values greater than 130 HU in the corticomedullary phase had high predictive values of metastasis (100% [11/11]), although only 26.2% (11/42) of metastatic adrenal masses met the criteria.”

“We calculated the attenuation difference between renal and adrenal masses on the hypothesis that the difference would be smaller in metastases than other adrenal masses because the metastatic site usually follows the characteristics of the primary tumor. As we speculated, the attenuation difference was statistically significantly smaller in metastatic adrenal masses than in benign adrenal masses in both the corticomedullary phase and nephrographic phase.”

“In the univariate analysis, the attenuation difference was useful for the prediction of benignity when the difference was large; the attenuation difference larger than 40 HU in the corticomedullary phase had high predictive values of benignity. In addition, the absolute values of the attenuation difference were statistically significant variables in the multivariate logistic regression models of both the corticomedullary phase and nephrographic phase. On the other hand, the attenuation difference was less useful in the prediction of metastasis when the difference was small because of large overlap with benign adrenal masses.”

“Ectopic ureter is defined as a ureter opening caudal to the bladder trigone. Ectopic ureter is the result of the ureteric bud arising from the mesonephric duct more cranially than usual. Ectopic insertion of a ureter of a single collecting system is rare. Over 80% of ectopic ureters are associated with duplicated systems and involve the upper moiety ureter.”

"In patients with ccRCC, observation of extensive necrosis on CT was statistically significantly associated with decreased disease-specific PFS, whereas greater tumor size and the presence of renal vein invasion on CT were statistically significantly associated with decreased DSS and disease-specific PFS. No disease progression was observed in tumors with a cystic appearance. Therefore, selected CT features could potentially aid in risk assessment for and counseling of patients with ccRCC and could provide prognostic information beyond the established tumor staging system." Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival Andreas M. Hötker et al. AJR 2016; 206:1023-1030

"Greater tumor size and the presence of renal vein invasion on CT were associated with decreased DSS and disease-specific PFS (p < 0.05), and the presence of extensive necrosis (more than two-thirds of the tumor volume) was associated with decreased disease- specific PFS (p < 0.05); this association remained statistically significant when we controlled for pathologic tumor stage. In contrast, no disease-specific death or progression was seen in patients with purely cystic tumors. Greater distance between the tumor and the renal sinus was not statistically significantly associated with longer survival." Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival Andreas M. Hötker et al. AJR 2016; 206:1023-1030

"Specific genomic mutations, some of which are known to affect patient outcome (e.g., a higher rate of renal vein in- vasion in tumors with mutations of KDM5C and BAP1 [BRCA1-associated protein-1]) have already been shown to have an effect on the appearance of renal cortical tumors on imaging; however, the association between renal tumor imaging features and patient survival has not yet been comprehensively investigated."Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival Andreas M. Hötker et al. AJR 2016; 206:1023-1030

" In patients with ccRCC, observation of extensive necrosis on CT was statistically significantly associated with decreased disease-specific PFS, whereas greater tumor size and the presence of renal vein invasion on CT were statistically significantly associated with decreased DSS and disease-specific PFS. No disease progression was observed in tumors with a cystic appearance. Therefore, selected CT features could potentially aid in risk assessment for and counseling of patients with ccRCC and could provide prognostic information beyond the established tumor staging system." Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival Hötker AM et al. AJR 2016; 206:1023-1030

" When including only preoperatively available CT features in multivariable analysis, only the maximum tumor length and the presence of renal vein invasion remained statistically significantly associated with shorter DSS and disease-specific PFS (progression-free survival )." Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival Hötker AM et al. AJR 2016; 206:1023-1030

"When we stratified our data by tumor size and included only CT features in the multi- variable model, the presence of gross renal vein invasion also remained a strong indicator of an elevated risk for disease progression, albeit only for tumors larger than 4 cm; this is probably because renal vein invasion is very rarely seen in tumors 4 cm or smaller (e.g., it was noted only in two patients in the present study)." Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival Hötker AM et al. AJR 2016; 206:1023-1030

"Of interest, we did not see any disease- specific progression or death among patients with purely cystic tumors. This is perhaps because these tumors belong to the distinct subgroup of multilocular cystic ccRCC, a rare, low-grade tumor that is known to have a favorable prognosis and that has been shown to have a distinct genomic make-up. Tumors in this subgroup lack mutations in SETD2, KDM5C, and BAP1, which are known to be negative prognostic fac- tors when found in solid tumors." Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival Hötker AM et al. AJR 2016; 206:1023-1030

"Although we found that tumor size, renal vein invasion, and extensive necrosis could be useful in risk assessment performed for patients with ccRCC who underwent surgery, and although we observed that cystic tumor appearance seemed to be associated with a favorable prognosis, the other features that were investigated (i.e., tumor contact with the renal sinus, peritumoral stranding, and neovascularity) were of no additive value in multivariable analysis, even though they were statistically significantly associated with patient survival in univariate analysis." Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival Hötker AM et al. AJR 2016; 206:1023-1030

"In conclusion, we found that tumor size, the presence of gross renal vein invasion, and the presence of extensive necrosis affected outcome for patients with ccRCC who underwent surgery and provided additive prognostic information beyond pathologic tumor stage. In contrast, we found no disease-specific progression in patients with tumors of purely cystic appearance. Thus, reporting of these CT features might allow more accurate risk stratification in patients with ccRCC." Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival Hötker AM et al. AJR 2016; 206:1023-1030

"Tuberous Sclerosis (TS) is inherited in an autosomal dominant fashion. It has a prevalence of 1 per 10,000 people and is characterized by a diverse array of abnor- malities. Renal angiomyolipomas, which are now classified as perivascular epithelial cell tumors (PEComas) are seen in as many as 80% of patients affected by TS. Renal cysts are seen in up to half of TS patients, while clear cell RCC is found in 2% to 4% of patients."

"Birt-Hogg-Dube Syndrome is also an autosomal dominant disorder, but has a prevalence of only 1 per 200,000 people. Approximately 15% to 30% of patients will develop renal carcinomas which are variable in his- tology with 34% chromophobe, 9% clear cell, 5% oncocytoma, and 2% papillary. In as many as 50% of patients, the tumors will contain mixed elements of oncocytoma and chromophobe RCC."

"Renal Medullary Carcinoma is a rare tumor arising from the distal collecting duct in patients with sickle cell trait. It is found in young adults and is often meta- static at time of presentation. Median survival from time of diagnosis is less than 4 months. There are no other associated abnormalities."

CT of Metastatic Renal Cell Carcinoma: Facts- Sunitinib is routinely used in patients with advanced renal cell carcinoma- Diarrhoea is the most common reported adverse event during sunitinib treatment. - Incidence of bowel oedema and diarrhoea during sunitinib treatment is correlated. - Radiologists should avoid misinterpretation of bowel oedema as infectious colitis.

OBJECTIVES: The purpose of this study was to retrospectively assess the incidence of bowel wall oedema on computed tomography (CT) in patients with renal cell carcinoma (RCC) treated with sunitinib, and to investigate its association with diarrhoea. CONCLUSIONS: This study shows a very high incidence of bowel wall oedema and a strong correlation between the incidence of bowel wall oedema and diarrhoea in patients treated with sunitinib.

“There was a statistically significant correlation between the incidence of CT-scored bowel oedema and diarrhoea during sunitinib treatment (P = 0.004).” “This study shows a very high incidence of bowel wall oedema and a strong correlation between the incidence of bowel wall oedema and diarrhoea in patients treated with sunitinib.”

“Renal cell carcinoma (RCC) represents about 3% of all malignant tumors. Metastasis is a strong predictors in patients with RCC. Common sites of RCC metastasis are the lung, lymph nodes, bone, and liver. Conversely, cardiac metastasis of RCC is an exceptional event with only a few cases reported worldwide to date, although cardiac involvement via the inferior vena cava (IVC) thrombi is well-known.”

“Cardiac metastases of RCC seem to occur through two mechanisms. The first is a venous hematogenous pathway through the renal vein to the right heart. In cases with isolated disease, delayed progression to the right heart, without involvement of the IVC, remains the most probable mode of metastasis through venous hematogenous microdissemination. The second mechanism involves a lymphatic pathway through the lymphatic vessels of the thorax, involving the carinal lymph nodes and parasternal lymph vessels. Reports have mentioned that drainage from the left heart wall passes through these lymph vessels, and lymphatic flow can be reversed by metastasis to the nodes. This hypothesis is supported by the fact that disseminated disease progression involves the supradiaphragmatic and mediastinal lymph nodes and the lungs, and the side of the heart involved more frequently is the left side.”

“Osseous metastases of renal cell carcinoma (RCC) are the second most frequent location after lung metastases. They rarely present as isolated location. When isolated, resection may offer five-year survival rates of 30-60%.”

“RCC bone metastases (BM) represent the second most common metastatic location after pulmonary metastases (20–40%) . Isolated BM are rare (0.7–2.5%) . Isolated bone metastasis is reported to be a good prognostic factor, with five-year survival varying between 30% and 60%. RCC isolated thoracic wall metastases are published as case reports. Isolated rib metastatic location of RCC is rare and remains not well-known. RCC thoracic wall metastases are also manly associated with other organ metastatic locations (8–4.5%).”

“Radical surgical treatment is considered the best approach for isolated BM of RCC. In fact, compared to other therapeutic approaches, wide surgical resection provides the best five-year survival rates. Wide resection was performed in all patients. To insure a complete and free margin resection we performed the resection of the rib below and the one under the metastatic rib. All resected tumors were metastases of a RCC. All resection margins were free from tumor cells.”

“The mechanism of cell tumor spread to bone in RCC is still unknown. The most commonly held hypothesis is that BM arise by hematogenous spread due to vascular invasion by the primary renal carcinoma. Lymphatic spread could be another mode of cancer cell dissemination. Renal lymphatic drainage is mostly directed to the thoracic duct. Renal tumor cells can further flow into the blood circulation. Lymphatic drainage of intercostal space is directed into the thoracic duct.”

“Sarcomatoid differentiation can occur in all major subtypes of RCC, including clear cell, papillary, and chromophobe tumors. Sarcomatoid RCCs are aggressive. Patients with sarcomatoid RCC have the worst prognosis of all renal tumor patients, and the presence of sarcomatoid RCC is an independent predictor of decreased survival with increasing amounts of sarcomatoid RCC associated with an increasingly worse prognosis.” Diagnosis of Sarcomatoid Renal Cell Carcinoma With CT: Evaluation by Qualitative Imaging Features and Texture Analysis. Schieda N et al. AJR Am J Roentgenol. 2015 May;204(5):1013-23

“Overall, sarcomatoid RCCs were significantly larger than clear cell RCCs in this study. Larger peritumoral vessels were observed more frequently in sarcomatoid RCCs than in clear cell RCCs. Sarcomatoid RCCs also showed distinct texture analysis features that could en- able diagnosis with high diagnostic accuracy. Further study of CT quantitative texture analysis techniques in renal masses is necessary, and validation of our preliminary observations in a larger patient cohort is required before imple- mentation in clinical practice.” Diagnosis of Sarcomatoid Renal Cell Carcinoma With CT: Evaluation by Qualitative Imaging Features and Texture Analysis. Schieda N et al. AJR Am J Roentgenol. 2015 May;204(5):1013-23

“Our results suggest that quantitative texture analysis is more accurate than visual analysis when assessing the heterogeneity of sarcomatoid RCCs compared with clear cell RCCs. Although the sarcomatoid RCCs were subjectively considered more heterogeneous than the clear cell RCCs, the difference was not statistically significant; however, the quantitative texture analysis depicted a statistically significant difference in the heterogeneity of the sarcomatoid RCCs and the clear cell RCCs.” Diagnosis of Sarcomatoid Renal Cell Carcinoma With CT: Evaluation by Qualitative Imaging Features and Texture Analysis. Schieda N et al. AJR Am J Roentgenol. 2015 May;204(5):1013-23

“In the United States, incidence of kidney and renal pelvis cancer is on the rise, with an estimated 63,920 new cases and 13,860 new deaths by these cancers in 2014. Hereditary renal cancer syndromes account for approximately 2–5% of RCCs.” Diagnostic approach to hereditary renal cell carcinoma. Gupta S et al. AJR 2015 May;204(5):1031-41

“Medullary carcinoma accounts for less than 1% of RCCs and is histologically similar to collecting duct carcinoma, exhibiting both a desmoplastic reaction and mucin production. However, unlike collecting duct carcinomas, medullary carcinomas contain cribriform glands. In patients with sickle cell trait, hypoxia in the renal medulla often leads to transitional cell proliferation within the terminal collecting ducts and papillary epithelium. It is thought that the epithelial proliferation leads to the development of medullary carcinomas . Grossly, these carcinomas are tan-gray and have a firm, rubbery consistency.” Diagnostic approach to hereditary renal cell carcinoma. Gupta S et al. AJR 2015 May;204(5):1031-41

“VHL syndrome is the most common hereditary RCC syndrome. In Europe and North America, the prevalence of VHL syndrome is 1 in 36,000–40,000. VHL syndrome has greater than 90% penetrance at 65 years of age. Among patients with VHL syndrome, RCC develops in 25–40% at an average age of 39 years, much earlier than the average age of 61 years for the presentation of sporadic RCCs.” Diagnostic approach to hereditary renal cell carcinoma. Gupta S et al. AJR 2015 May;204(5):1031-41

“Patients with VHL syndrome present with multiple and bilateral renal lesions, including as many as 600 tumors and 1100 cysts per kidney . Although hundreds of tumors and cysts may be found in each kidney, only some can be seen on imaging, and even fewer are clinically significant. Metastases can be seen if solid clear cell RCCs are left untreated, particularly if the RCCs are larger than 3 cm.” Diagnostic approach to hereditary renal cell carcinoma. Gupta S et al. AJR 2015 May;204(5):1031-41

“In the abdomen, the most commonly visualized extrarenal lesions are pancreatic serous cystadenomas, which can present with exocrine insufficiency, abdominal pain, decreased appetite, or a combination of these signs and symptoms. Serous cystadenomas classically have a honeycomb appearance due to numerous small cysts and thin septations with a fibrous or calcified central scar that may or may not be enhancing. Pancreatic neuroendocrine tumors and pheochromocytomas occur in less than 8% of patients with VHL syndrome. The average life expectancy of a patient with VHL syndrome is less than 50 years.” Diagnostic approach to hereditary renal cell carcinoma. Gupta S et al. AJR 2015 May;204(5):1031-41

“Tuberous sclerosis has an incidence at birth of 1 in 6000–10,000. Most cases of tuberous sclerosis are a result of spontaneous mutation. Approximately 30% are inherited as autosomal dominant disorders with near-complete penetrance and variable expressivity. RCC develops in only 1–4% of patients with tuberous sclerosis.” Diagnostic approach to hereditary renal cell carcinoma. Gupta S et al. AJR 2015 May;204(5):1031-41

“Angiomyolipomas are the most common and distinguishing renal lesions in tuberous sclerosis, occurring in 70–80% of tuberous sclerosis patients older than 10 years. The distribution of these lesions is multiple and bilateral. Angiomyolipomas can cause hematuria, mass effect, hypertension, and renal insufficiency. Acute hemorrhage is the most concerning risk associated with angiomyolipoma, particularly if the angiomyolipoma is larger than 4 cm. The numerous renal cysts can cause pain, infection, and renal insufficiency, particularly in cases associated with polycystic renal disease. RCCs occur in 1–4% of tuberous sclerosis patients and usually present at an average age of 28 years in a multiple, bilateral pattern. The principal RCC associated with tuberous sclerosis is clear cell, although papillary and chromophobe RCCs and oncocytomas may also occur.” Diagnostic approach to hereditary renal cell carcinoma. Gupta S et al. AJR 2015 May;204(5):1031-41

“Radiologists may be the first to suggest the diagnosis of a hereditary RCC syndrome, which should be suspected if a patient has multiple RCCs or bilaterally distributed or early onset (< 50 years) RCC. A pattern-based approach incorporating imaging features of the predominant tumor subtype with certain associated findings may help radiologists differentiate the various hereditary RCC syndromes.” Diagnostic approach to hereditary renal cell carcinoma. Gupta S et al. AJR 2015 May;204(5):1031-41

Hereditary Renal Cell Carcinoma

“The renal manifestations of tuberous sclerosis include angiomyolipomas, renal cysts, and renal cell carcinoma (RCC). Angiomyolipomas are the most common benign mesenchymal neoplasm and are composed of varying amounts of fat, smooth muscle, and blood vessels. Angiomyolipomas are present in 80% of patients with tuberous sclerosis. Angiomyolipomas due to tuberous sclerosis typically occur in younger patients and are frequently multiple and bilateral. Conversely, approximately 20% of patients with angiomyolipomas have tuberous sclerosis. The remainder of angiomyolipomas are sporadic (nontuberous sclerosis). Sporadic angiomyolipomas are usually unilateral and solitary and occur in middle-aged women. In addition, 2–3% of patients with tuberous sclerosis may have multiple renal cysts, given the proximity of the TSC2 gene to one of the genes on chromosome 16p13 that encodes for autosomal dominant polycystic kidney disease.” Comprehensive imaging manifestations of tuberous sclerosis. Manoukian SB, Kowal DJ. AJR Am J Roentgenol. 2015 May;204(5):933-43

“The renal manifestations of tuberous sclerosis include angiomyolipomas, renal cysts, and renal cell carcinoma (RCC). Angiomyolipomas are the most common benign mesenchymal neoplasm and are composed of varying amounts of fat, smooth muscle, and blood vessels. Angiomyolipomas are present in 80% of patients with tuberous sclerosis. Angiomyolipomas due to tuberous sclerosis typically occur in younger patients and are frequently multiple and bilateral. Conversely, approximately 20% of patients with angiomyolipomas have tuberous sclerosis. The remainder of angiomyolipomas are sporadic (nontuberous sclerosis). Sporadic angiomyolipomas are usually unilateral and solitary and occur in middle-aged women.” Comprehensive imaging manifestations of tuberous sclerosis. Manoukian SB, Kowal DJ. AJR Am J Roentgenol. 2015 May;204(5):933-43

“Most renal angiomyolipomas are asymptomatic. However, patients can present with flank pain, hematuria, hemorrhage, or a tender abdominal mass. Renal angiomyolipomas are the second most common cause of morbidity and mortality among patients with tuberous sclerosis. This risk can be attributed to an increased risk of rupture or hemorrhage of angiomyolipomas larger than 4 cm and aneurysms larger than 5 mm occurring within these tumors. If either of these criteria is met, treatment consists of resection or embolization. Tumors smaller than 4 cm are followed conservatively.” Comprehensive imaging manifestations of tuberous sclerosis. Manoukian SB, Kowal DJ. AJR Am J Roentgenol. 2015 May;204(5):933-43

“The incidence of RCC among people with tuberous sclerosis is similar to that in the general population (2–3%) . However, the age at onset is much younger, and RCC in these patients tends to grow more slowly. The average age at diagnosis of RCC in tuberous sclerosis patients is 28 years, which is 25 years younger than in the general population. Tuberous sclerosis–associated RCCs are predominantly clear cell RCCs, but papillary and chromophobe RCCs have also been reported in the literature. The patterns of CT attenuation and homogeneity depend on the subtype, microvessel density, and presence of intratumoral necrosis or hemorrhage. Clear cell carcinomas are hypervascular and typically exhibit heterogeneous early enhancement and early washout. Papillary carcinomas tend to be hypovascular, usually enhancing in a gradual manner.” Comprehensive imaging manifestations of tuberous sclerosis. Manoukian SB, Kowal DJ. AJR Am J Roentgenol. 2015 May;204(5):933-43

“The incidence of RCC among people with tuberous sclerosis is similar to that in the general population (2–3%) . However, the age at onset is much younger, and RCC in these patients tends to grow more slowly. The average age at diagnosis of RCC in tuberous sclerosis patients is 28 years, which is 25 years younger than in the general population. Tuberous sclerosis–associated RCCs are predominantly clear cell RCCs, but papillary and chromophobe RCCs have also been reported in the literature.” Comprehensive imaging manifestations of tuberous sclerosis. Manoukian SB, Kowal DJ. AJR Am J Roentgenol. 2015 May;204(5):933-43

Pearls and Pitfalls- The most common errors in the evaluation of the renal arteries are basic and revolve around poor protocol design and execution (poor data acquisition timing or patient motion)and the lack of routine MPR and 3D imaging- Interpretation errors are more common in patients with complex vascular anatomy and patients with larger tumors or masses.

“ Chromophobe RCCs were found to have a wider variability of CT features than previously reported, although they do have a greater propensity for homogeneity and the presence of a central scar or necrosis. Their enhancement characteristics fall in between those of clear cell and papillary RCC, although there is considerable overlap.”Chromophobe Renal Cell Carcinoma: Multiphase MDCT Enhancement Patterns and Morphologic FeaturesRaman SP, Johnson PT, Allaf ME, Netto G, Fishman EKAJR 2013; 201:1268-1276

“ Chromphobe RCCs are most likely to present as a well circumscribed relatively homogeneous mass, often with a central scar and an enhancement pattern that is hypovascular relative to papillary variants In some cases raising the possibility of this diagnosis prospectively may be clinically useful, because nephron sparing surgery should certainly be considered for those tumors given their almost universally positive prognosis.”Chromophobe Renal Cell Carcinoma: Multiphase MDCT Enhancement Patterns and Morphologic FeaturesRaman SP, Johnson PT, Allaf ME, Netto G, Fishman EKAJR 2013; 201:1268-1276

Chromophobe Renal Cell Carcinoma: Facts- Account for 4-6% of renal cell carcinomas- 60% of patients are male- Mean age is 60.2 years- 46% were incidental findings without clinical symptoms- Metastases are rare at presentation and at followup (5 year survival over 90%)- Lesions are usually relatively hypovascular

“ Segmental enhancement inversion was not a common or characteristic CT finding for renal oncocytoma and was not helpful in differentiating small renal oncocytomas from RCC.”Small Renal Oncocytomas: Is Segmental Enhancement Inversion a Characteristic Finding at Biphasic MDCT?O’Malley ME et al.AJR 2012; 199:1312-1315

Segmental Enhancement Inversion : Definition- “when a renal mass can be subdivided into two distinct segments showing different degrees of enhancement during the corticomedullary phase, with the relatively highly enhanced segment becoming less enhanced during the nephrographic phase and the less enhanced segment during the corticomedullary phase become more enhanced during the nephrographic phase.”- Segmental enhancement inversion at biphasic multidetector CT: characteristic finding of small renal oncocytoma- Kim JI et al- Radiology 2009;252:441-448

“ Multiphase MDCT with multiplanar reconstructions has satisfactory results in the detection of renal pseudocapsule in RCC.”Renal Cell Carcinoma: Value of Multiphase MDCT With Multiplanar Reformations in the Detection of PseudocapsuleTsili AC et al.AJR 2012; 199:379-386

“ The presence of pseudocapsule surrounding RCC is considered a histologic feature of early-stage disease. Pathologically, renal pseudocapsule is composed of fibrous tissue and compressed renal parenchyma.”Renal Cell Carcinoma: Value of Multiphase MDCT With Multiplanar Reformations in the Detection of PseudocapsuleTsili AC et al.AJR 2012; 199:379-386

“ A more conservative approach, including nephron sparing surgery or simple enucleation, may be preferred for these patients.”Renal Cell Carcinoma: Value of Multiphase MDCT With Multiplanar Reformations in the Detection of PseudocapsuleTsili AC et al.AJR 2012; 199:379-386

“ A more conservative approach, including nephron sparing surgery or simple enucleation, may be preferred for these patients.However in some large aggressive RCCs with neoplastic invasion, residual pseudocapsule may be found at pathologic examination.”Renal Cell Carcinoma: Value of Multiphase MDCT With Multiplanar Reformations in the Detection of PseudocapsuleTsili AC et al.AJR 2012; 199:379-386

“ Given their prevalence, the vast majority of renal masses encountered by a radiologist are likely to represent renal cell carcinomas, AMLs, or transitional cell carcinomas. However, as the cases we have presented illustrate, there are a large number of other lesions which can affect the kidneys, many of which have vastly different prognoses and clinical outcomes.”Beyond Renal Cell Carcinoma: Rare and Unusual Renal MassesRaman SP, Hruban RH, Fishman EKAbdom Imaging (2012)

“ Given their prevalence, the vast majority of renal masses encountered by a radiologist are likely to represent renal cell carcinomas, AMLs, or transitional cell carcinomas. However, as the cases we have presented illustrate, there are a large number of other lesions which can affect the kidneys, many of which have vastly different prognoses and clinical outcomes. While the radiologist may not be able to make a specific diagnosis in most cases, knowledge of these lesions may allow the radiologist to suggest an alternative possible diagnosis.”Beyond Renal Cell Carcinoma: Rare and Unusual Renal MassesRaman SP, Hruban RH, Fishman EKAbdom Imaging (2012)

“ However, as the cases we have presented illustrate, there are a large number of other lesions which can affect the kidneys, many of which have vastly different prognoses and clinical outcomes. While the radiologist may not be able to make a specific diagnosis in most cases, knowledge of these lesions may allow the radiologist to suggest an alternative possible diagnosis.”Beyond Renal Cell Carcinoma: Rare and Unusual Renal MassesRaman SP, Hruban RH, Fishman EKAbdom Imaging (2012)

“Imaging follow-up protocls should be tailored according to the clinical scenario. Further experience is necessary to better refine imaging strategies, especially regarding follow-up of patients after thermal ablation or antiangiogenic therapy and those being maintained on active surveillance.”Imaging in the Follow-Up of Renal Cell CarcinomaPatel U, Sokhi HAJR 2012; 198:1266-1276

When do you do follow-up CT for Renal Cell Carcinoma?Typical protocols may vary depending on the patients mode of therapy- After nephrectomy- After ablative therapy- After receiving chemotherapy- The frequency of imaging is stage dependent but no clear plan is accepted by all societies

“ Local recurrence was seen in 2.7% of patients after partial nephrectomy in one series and was quoted as less than 3-5% elsewhere.”Imaging in the Follow-Up of Renal Cell CarcinomaPatel U, Sokhi HAJR 2012; 198:1266-1276

“ Even after successful surgical or ablative therapy, up to 5% of patients with sporadic RCC and without a recognized hereditary risk factor will develop a metachronous RCC.”Imaging in the Follow-Up of Renal Cell CarcinomaPatel U, Sokhi HAJR 2012; 198:1266-1276

“ The average maximum unenhanced ROI attenuation for all lesions was 39.7 ± 10.6 HU (range 21-80 HU), and the average minimum ROI attenuation was 27.5 ± 10.4 HU (range 4-67 HU). Minimum ROI attenuation was less than 20HU in 24.9% of tumors and maximum ROI was greater than 70HU in 2.1% of tumors”Renal Cell Carcinoma: Attenuation Values on Unenhanced CTPooler BD et al.AJR 2012; 198:1115-1120

“ Given that renal lesions completely outside this range have proven to be benign in previous work, we conclude that indeterminate renal lesions on unenhanced CT that contain areas of ROI attenuation that cross over into this 20-70 HU danger zone will generally warrant further workup.”Renal Cell Carcinoma: Attenuation Values on Unenhanced CTPooler BD et al.AJR 2012; 198:1115-1120

Partial Nephrectomy: Patient Selection- Previously tumor was 4 cm or less and now 7 cm is the usual cutoff (T1 tumor)- Partial nephrectomy can be used in T2 tumors (> 7cm) in select cases such as solitary kidney or overall poor renal function and the need to “save kidney”- Location of tumor is then a critical factor in selecting patients for partial nephrectomy

“ Clinical node staging is inaccurate. The positive predictive value of the finding of nodes larger than 1 cm on preoperative imaging is only 42%.”Renal Cell Carcinoma: What the Surgeon and Treating Physician Need to KnowChapin BF et al.AJR 2011; 196:1255-1282

Partial Nephrectomy: Patient Selection- Previously tumor was 4 cm or less and now 7 cm is the usual cutoff (T1 tumor)- Partial nephrectomy can be used in T2 tumors (> 7cm) in select cases such as solitary kidney or overall poor renal function and the need to “save kidney”- Location of tumor is then a critical factor in selecting patients for partial nephrectomy

“ Clinical node staging is inaccurate. The positive predictive value of the finding of nodes larger than 1 cm on preoperative imaging is only 42%.”Renal Cell Carcinoma: What the Surgeon and Treating Physician Need to KnowChapin BF et al.AJR 2011; 196:1255-1282

Recurrent Renal Cell Carcinoma: Facts- Metastases can occur early in the post operative course (under 1 year) as well as late in the post-operative course (over 10 years later)- Metastases tend to follow the vascularity of the primary tumor and most are hypervascular- Arterial phase CT is critical in lesion detection especially in liver and pancreas

"Patients with renal cell carcinoma in whom multidetector computerized tomography fails to detect tumor thrombus are unlikely to have a tumor thrombus found at surgery that would change the surgical approach."

Abstract

PURPOSE: New advances in computerized tomography, including multidetector computerized tomography with 3-dimensional reformatting has recently called into question the absolute need for magnetic resonance imaging for evaluating renal cell carcinoma with suspected venous involvement. We assessed the accuracy of multidetector computerized tomography for predicting tumor thrombus and the level of venous involvement in patients with renal cell carcinoma.

MATERIALS AND METHODS: We retrospectively reviewed clinical and pathological features in 41 patients with renal cell carcinoma who underwent staging multidetector computerized tomography before surgery. Multidetector computerized tomography findings regarding the presence and level of tumor thrombus were compared to findings at surgery and at final pathological evaluation. All multidetector computerized tomography studies were read by a single radiologist (EKF) before surgery.

RESULTS: When excluding patients with segmental venous involvement only, the concordance rate between multidetector computerized tomography and pathological findings was 84%. Multidetector computerized tomography accurately predicted the level of tumor thrombus in 26 of 27 patients (96%). Four cases of negative multidetector computerized tomography findings were up staged to renal vein involvement based on pathological findings. All 4 patients had early distal thrombi that did not change operative management.

CONCLUSIONS: Multidetector computerized tomography with 3-dimensional mapping is an effective imaging modality for accurately characterizing the level of venous thrombus in patients with renal cell carcinoma. This modality effectively identified patients with clinically significant venous thrombus. Patients with renal cell carcinoma in whom multidetector computerized tomography fails to detect tumor thrombus are unlikely to have a tumor thrombus found at surgery that would change the surgical approach.

Renal Cell Carcinoma: Stage IV (any of these)- Tumor that has spread directly through the fatty tissue and the fascia ligament-like tissue that surrounds the kidney. Involvement of more than one lymph node near the kidney- Involvement of any lymph node not near the kidney- Distant metastases, such as in the lungs, bone, or brain.

Renal Cell Carcinoma: Stage III (either)- Tumor of any size with involvement of a nearby lymph node but no metastases to distant organs. Tumor of this stage may be with or without spread to fatty tissue around the kidney, with or without spread into the large veins leading from the kidney to the heart.- Tumor with spread to fatty tissue around the kidney and/or spread into the large veins leading from the kidney to the heart, but without spread to any lymph nodes or other organs.

Renal Cell Carcinoma: Stage II

Tumor larger than 7.0Â cm but still limited to the kidney. No lymph node involvement or metastases to distant organs.

Renal Cell Carcinoma: Stage I

Tumor of a diameter of 7Â cm (approx. 2 3/4Â inches) or smaller, and limited to the kidney. No lymph node involvement or metastases to distant organs.

Renal Cancer (RCC and TCC): Facts- 58,240 Americans will be diagnosed with renal cancer in 2010 and an estimated 13,040 will die from renal carcinoma in 2010. (Deaths worldwide are over 100,000 annually)- Over 40,000 of these cases and over 12,000 deaths will be due to renal cell carcinoma- Typical age is over 55 years and occurs more frequently in men- 92% of cases are clear cell renal cell carcinoma and around 8% are papillary type renal cell carcinoma

Renal Cancer (RCC and TCC): Facts- 58,240 Americans will be diagnosed with renal cancer in 2010 and an estimated 13,040 will die from renal carcinoma in 2010. (Deaths worldwide are over 100,000 annually)- Over 40,000 of these cases and over 12,000 deaths will be due to renal cell carcinoma- Typical age is over 55 years and occurs more frequently in men- 92% of cases are clear cell renal cell carcinoma and around 8% are papillary type renal cell carcinoma

irt-Hogg-Dube Syndrome: Facts- Rare autosomal dominant disease- Syndrome includes hair follicle hamartomas, renal tumors, and pulmonary cysts- Tumors usually occur at an earlier age and are multiple- Renal tumors are usually chromophobe RCC

"Tumor long axis measurements and volumetric mean tumor attenuation of target lesions on CECT images were correlated with time to progression in 53 patients with metastatic clear cell RCC treated with first line sorafenib or sunitinib."

"One or more target metastatic lesions had decreased attenuation of = 40 HU in 59% of patients with progression free survival of >250 days after initiating targeted therapy; 0% of patients with earlier disease progression had this finding."

"Objectively measuring changes in both tumor size and attenuation on the first CECT after initiating targeted therapy for metastatic RCC markedly improves response assessment. Distinct patterns of disease recurrence are seen in patients with metastatic RCC on targeted therapy."

"Patients with highly vascularized metastatic RCC as shown by high baseline tumor blood flow appear to have a worse prognosis than those who do not. Tumor perfusion may be a useful biomarker of prognosis and additionally in the future, may assist in treatment stratification."